抄録
In open-channel turbulent flows with a rough wall, water surface profiles can be affected by the relative size of roughness element to a water depth and arrangement of roughness elements. In order to find characteristics of water surface profiles under various hydraulic conditions, an experimental study by using a simple surface flow visualization technique and a numerical study based on a large eddy simulation model that can take into account of water surface deformation were conducted for a rough wall boundary. Hemisphere particles were used as candidate of roughness elements for simplicity of establishing several particle distribution densities. It was made clear that water surface pattern can be classified by five types: flat, ripples, advection, parallel and cross. For sparse roughness elements, LES was conducted successfully to reproduce the above surface patterns.
